Describe your 1990 Oldsmobile Ninety Eight Problem timing chain replacement

If you replaced only the coils, and not the module beneath, you wasted your time. Most times the module is what causes this.

Any decent auto wrecker should have a dozen of those, or ebay.

It is possible the timing chain could have jumped or stripped a gear.Have them to check compression.Could also have them check the cam and crank sensors.Let me know what they find.Good luck.

Replace the crank pulley aka. balancer, they fall apart and knock.

if you are not experienced mech. maybe you should take it to one

It has a timing chain.Hope this helps.Good luck.

cam sensor is only half of the cam circuit, the other half of the cam circuit is the magnet on the timing chain. the cam sensor reads from the magnet every time the engine completes a revolution,
what happens is the magnet on the chain will break into smaller piece which makes the sensor harder to read every time the engine make a complete revolution.
most likely you'll need to replace the timing chain to fix this.

It should tell you on the driver door or the panel by the door. Along with Tire information. My guess would be between 4k and 5k lbs. If you can't find it then google vehicle weight. I think the website is autospecs.com or vehiclespecs.com. There are sites that have that info.

Check egr valve, check pvc valve, check head gasket, check air filter, timing timing out of adjustment, burned valves or leaking, cam shafts could be worn, check fuel enjectors.

that happened to me and I solved the problem by replacing the computer. It cost me $40.00 out of a junk yard and it has been running perfect ever since.